Liver Fibrosis Assessment by Ultrasound Elastometry in Thalassemic Patients on Long-Term Iron Chelation.

BACKGROUND

In thalassemic major patients liver fibrosis may be influenced by independent factors as hepatitis, degree of iron loading and iron chelation, and the specific effect of drugs. Due to its invasive nature, the histological evaluation of liver fibrosis on biopsy samples is difficult to be done and repeated. We analysed the relationship of these factors with the degree of liver fibrosis assessed non-invasively by ultrasound elastometry expressed as liver stiffness. We also compared the liver stiffness in patients on long term therapy with different iron chelators.

METHODS

We applied the ultrasound elastometry (Fibroscan®, Fibrosens, Paris) to a consecutive series of patients with ß thalassemia major on regular transfusion and chelation. Liver Iron Concentration (LIC) has been assessed by SQUID magnetic susceptometry (Tristan Technologies, Inc., San Diego, USA). We considered, as control, a group of healthy persons. All the subjects signed a written informed consent.

RESULTS

We studied 115 patients (64 males, 51 females) with beta thalassemia major, with mean age of 27.7 ± 7.6 years (range: 6.7–48.3). Eighty-six (75%) patients were HCV-Ab positive, and 52 (45%) HCV-RNA positive. Mean stiffness was 9.0 ± 6.6 KPa (range 3.3–43.5), significantly higher than in controls (4.0 ± 1.0, CI 3.3–4.8). Seven (6%) patients had a stiffness value above the cirrhosis threshold, and 18 (16%) were above the severe fibrosis threshold. Mean serum ferritin was 2064 ± 2011 μg/L, and mean LIC was 1845 ± 1199 microg/g ww. Considering the chelator, 34 patients have been on deferoxamine (DFO) therapy for 19.2 ± 9 years, 53 patients on deferiprone (L1) for 5.7 ± 3.7 years, and 28 on deferasirox (ICL670) for 3.3 ± 1.1 years. Mean stiffness was 9.5 ± 7.4 kPa, 9.9 ± 7.3 and 6.6 ± 2.8, respectively. On multivariate analysis, HCV Ab, HCV RNA and LIC were independent factors determining the degree of stiffness, while the chelator used was not significant.

CONCLUSIONS

Thalassemia major patients on regular transfusion and chelation have significantly abnormal degree of liver fibrosis. HCV positivity and the amount of iron overload seem to be the main related factors. The type of chelator used does not seem important.